PACKER: a switchbox router based on conflict elimination by local transformations

PACKER is an algorithm for switchbox routing, based on a novel approach. In an initial phase, the connectivity of each net is established without taking the other nets into account. In general, this gives rise to conflicts (short circuits). In the second stage, the conflicts are removed iteratively using connectivity-preserving local transformations. They reshape a net by displacing one of its segments without disconnecting it from the net. The transformations are applied in a asystematic way using a scan line technique. The results obtained by PACKER are very positive: it solves all well-known benchmark example

Modeling and Compensation of Nonlinear Distortion in Horn Loudspeakers

Horn loaded compression drivers are widely used in the area where high sound pressure levels together with good directivity characteristics are needed. Major disadvantage of this kind of drivers is the considerable amount of nonlinear distortion. Due to the quite high air pressures in the driver the air is driven into its nonlinear range. This paper describes a technique to reduce the distortion caused by this phenomenon. Using a Digital Signal Processor (DSP), a feedforward compensation technique, based on an equivalent lumped parameter circuit, is implemented and tested in real–time in series with the loudspeaker. Measurement and simulation results are given. The overall conclusion is that a distortion reduction is obtained in the frequency span from 600 to 1050 Hz

Dispersal of two moderately venomous spiders Cheiracanthium mildei and C. punctorium in Saxony and Brandenburg (Araneae: Miturgidae)

In the summers of 2006 and 2007 presumed bites of Cheiracanthium spiders triggered mass hysteria in Austria and some regions of Germany, including northern Saxonia. Here we report the first records of Cheiracanthium mildei L. Koch, 1864 from Saxony and new records of C. punctorium (Villers, 1789) from Saxony and Brandenburg. C. punctorium is probably a native species in southern Germany. It shows a moderate area expansion that could be driven by global warming. Further records in north-western Saxony are to be expected. By contrast, C. mildei has to be regarded an invasive alien species that has rapidly spread into Central Europe from the Mediterranean. Leipzig is the north-easternmost locality in Europe reached so far, a further 230 km away from Nuremberg, the leading edge in 2006. A number of records in different districts of Leipzig suggest that the species is already established in the town. We also report verified bites of both species. The mild to moderate symptoms are in accordance with recent literature reviews

Transferability of a random forest model for resistance prediction between different regions in Europe

Herbizide sind eine wichtige Komponente der integrierten Unkrautbekämpfung (IWM) in der modernen Landwirtschaft. Entscheidungshilfesysteme zur Bewertung des Risikos einer Resistenzentwicklung können in hohem Maße dazu beitragen, die beste IWM-Strategie zu wählen, die an die lokale Situation vor Ort angepasst ist. In einer vorherigen Studie (Herrmann et al., 2016) wurde ein „Random Forest“ Vorhersagemodell zur Bewertung des Risikos für das Auftreten von Resistenzen in Alopecurus myosuroides (ALOMY) Populationen in Süddeutschland erstellt, das auf langjährigen Schlaghistorien beruht. In der vorliegenden Studie wurde die Übertragbarkeit des Vorhersagemodells in Bezug auf Regionen und vergleichbare Unkräuter anhand eines ähnlichen Datensatzes aus einer Region in Nordfrankreich analysiert. Die französischen Daten enthalten auch Informationen zu Lolium spp. (LOLSS, hauptsächlich Lolium perenne). Die deutschen und französischen Daten wurden durch Austausch von Test- und Trainingsdaten einem Kreuzvalidierungsverfahren unterzogen. Die Ergebnisse zeigen, dass von Trainingsdaten aus Deutschland akzeptable Vorhersagen für Frankreich erhalten werden können und umgekehrt. Der Resistenzstatus von Proben von Lolium spp. aus Frankreich kann mit einer guten Genauigkeit anhand eines gemeinsamen Trainingssatzes von Proben von A. myosuroides aus Deutschland und Frankreich vorhergesagt werden.Herbicides are an important technology in the Integrated Weed Management (IWM) tool box aiming to control weeds in modern agriculture. Prediction tools to evaluate the risk of resistance evolution will greatly help to choose the best IWM strategy adapted to the local field situation. In a previous work (Herrmann et al., 2016) a random forest risk assessment model based on a data set comprising field history, management, and resistance status of Alopecurus myosuroides populations in Southern Germany was created. In this study transferability of the model with respect to regions and comparable weeds was analysed based on a similar dataset from a region in Northern France. The data from France also contained information on Lolium spp. The data related to Germany and France were subjected to a cross-validation procedure by interchanging test and training data. Results showed that acceptable predictions can be obtained for training data from Germany applied to France and vice versa. Resistance status in LOLSS samples from France can be predicted with a good accuracy based on a combined training set of A. myosuroides samples from Germany and France

Tropospheric Aqueous-Phase Oxidation of Isoprene-Derived Dihydroxycarbonyl Compounds

The dihydroxycarbonyls 3,4-dihydroxy-2-butanone (DHBO) and 2,3-dihydroxy-2-methylpropanal (DHMP) formed from isoprene oxidation products in the atmospheric gas phase under low-NO conditions can be expected to form aqSOA in the tropospheric aqueous phase because of their solubility. In the present study, DHBO and DHMP were investigated concerning their radical-driven aqueous-phase oxidation reaction kinetics. For DHBO and DHMP the following rate constants at 298 K are reported: k(OH + DHBO) = (1.0 ± 0.1) × 109 L mol-1 s-1, k(NO3 + DHBO) = (2.6 ± 1.6) × 106 L mol-1 s-1, k(SO4-+ DHBO) = (2.3 ± 0.2) × 107 L mol-1 s-1, k(OH + DHMP) = (1.2 ± 0.1) × 109 L mol-1 s-1, k (NO3 + DHMP) = (7.9 ± 0.7) × 106 L mol-1 s-1, k(SO4- + DHMP) = (3.3 ± 0.2) × 107 L mol-1 s-1, together with their respective temperature dependences. The product studies of both DHBO and DHMP revealed hydroxydicarbonyls, short chain carbonyls, and carboxylic acids, such as hydroxyacetone, methylglyoxal, and lactic and pyruvic acid as oxidation products with single yields up to 25%. The achieved carbon balance was 75% for DHBO and 67% for DHMP. An aqueous-phase oxidation scheme for both DHBO and DHMP was developed on the basis of the experimental findings to show their potential to contribute to the aqSOA formation. It can be expected that the main contribution to aqSOA occurs via acid formation while other short-chain oxidation products are expected to back-partition into the gas phase to undergo further oxidation there

A versatile algorithm for two-dimensional symmetric noncausal modeling

In this paper a novel algorithm is presented for the efficient two-dimensional (2-D) symmetric noncausal finite impulse response (FIR) filtering and autoregressive (AR) modeling. Symmetric filter masks of general boundaries are allowed. The proposed algorithm offers the greatest maneuverability in the 2-D index space in a computational efficient way. This flexibility can be taken into advantage if the shape of the 2-D mask is not a priori known and has to be dynamically configured

Linkage of the current ALS-resistance status with field history information of multiple fields infested with blackgrass (Alopecurus myosuroides Huds.) in southern Germany

The repetitive use of herbicides as major tool to control troublesome weeds in agriculture caused an increase in resistant weeds lately, especially when Integrated Weed Management principles were ingnored. In a case study approach we sampled blackgrass (Alopecurus myosuroides Huds.) in three distinctive locations for at least 3 years. Based on field infestation level, greenhouse biotests and laboratory analyses we grouped 23 fields as resitant (R), 28 fields as less sensitive (I) and 39 fields as sensitive (S) with regard to their ALS resistance status. Field history information was collected for 90 fields. Variables regarding the frequency of 1) summer crops, 2) winter cerals, 3) ploughing, 4) herbicide use, and 5) early versus late seeding were calculated. Fields with a higher frequency of summer crops, ploughing and later sowing dates in the crop rotation were less frequently grouped into R and I. No relationship was found between the number of modes of action used and the resistance status. Intensity of ALS-inhibitor use of grass herbicides played a role to distinguish resistant from sensitive fields. Our results suggest that cultural measures to bring the blackgrass population size to lower levels are more important than the selection by the herbicide.Zusammenhang des ALS-Resistenzstatus bei Ackerfuchsschwanz (Alopecurus myosuroides Huds.) mit den durchgeführten Bewirtschaftungsmaßnahmen auf mehreren Feldern in SüddeutschlandDer übermäßige Einsatz von Herbiziden als einzige Maßnahme zur Reduzierung von Problemunkräutern hat in den letzten jahren zu einer Zunahme resistenter Unkrautpopulationen geführt. Im Rahmen einer Fallstudie wurde daher Ackerfuchsschwanzsamen (Alopecurus myosuroides Huds.) an 3 Standorten über einen Zeitraum von mindetstens 3 Jahren beprobt. Basierend auf einer Befallseinschätzung im Feld, Gewächshaustests und Laboranalysen wurden 23 Felder als resistent (R), 28 Felder als vermindert sensitiv (I) und 39 Felder als sensitive Felder (S) gegenüber ALS-Inhibitoren klassifiziert. In Interviews mit den Landwirten konnten die Bewirtschaftungsmaßnahmen für diese 90 Felder erfragt werden. Aus diesen wurden Variablen, die den Anteil an 1) der Sommerungen in der Fruchtfolge, 2) des Wintergetreides in der Fruchtfolge, 3) den Pflugeinsatz, 4) den Herbizideinsatz sowie 5) die Saatzeitpunktewahl repräsentieren, generiert. Mit einer Zunahme an Sommerungen in der Fruchtfolge, einem erhöhten Pflugeinsatz sowie der häufigeren Wahl später Saatterminewar eine geringere Häufigkeit an resistenten Feldern zu beobachten. Dagegen wurde kein Zusammenhang zwischen der Anzahl der eingesetzten Wirkstoffklassen und dem Resistenzstatus gefunden. Signifikante Unterschiede beim Einsatz von ALS-Inhibitoren waren nur zwischen S und R erkennbar. Unsere Ergebnisse zeigen, dass ackerbauliche Maßnahmen eine stärkere Wirkung auf die Resistenzentwicklung haben, als die Häufigkeit and Art des Herbizid-Einsatzes

Cataract surgery with intraocular lens implantation in children aged 5-15 in local anaesthesia: visual outcomes and complications

The aim of this study was to report feasibility, the visual outcomes and complications of pediatric cataract surgery with primary intraocular lens implantation in children aged 5 to15 years in local anesthesia. This retrospective interventional case series included 62 eyes from 50 children who underwent pediatrc cataract surgery with primary intraocular lens implantation at the Mana eye Clinic Nkongsamba between 2006 and 2015 Main outcome measures were: best-corrected post operative visual acuity, and intraoperative and postoperative complications. Mean age at surgery was 10.18 ± 3.21 years. Mean follow up length was 15.75 ± 3.36 weeks. Etiology included: 10 congenital cataracs (16.12%). 35 developmental cataracts (56.45%) and 17 traumatic cataracts (27.41%). The mean preoperative BCVA was logMAR 1.19 ± 0.33. (range 0.6-2.3). After cycloplegia refraction 2 weeks after surgery, the mean postoperative BCVA was log MAR 0.58 ± 0.88 ( range 0.5-1.8). The mean implanted IOL power was 22.01 ±3.16 D. IOL was succefuly implanted in 54 eyes (87.07%). Eight eyes (9.67%) were left aphakic. Increase in BCVA of 4 logMAR lines and above was recorded in 27 patients (43.55%). Intraoperative complications included: 4 posterior capsule holes with vitrous lost, 3 lenses subluxation and 1 case of iris dialyse. Late postoperative complications included: posterior capsular opacity which occurred in 16 patients, 3 posterior synechia, 2 retinal detachment. Peribulbar anaesthesia can be considered as a viable option in selected patients presenting developmental cataract undergoing cataract surgery in developing countries. Effort should be made to improve the early identification of congenital cataract and its early surgical intervention and prompt optical rehabilitation to prevent amblyopia.Pan African Medical Journal 2016; 2